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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Posted on 9 June 2011 by John Cook

This article was originally published at ABC Environment yesterday. I'm doing my best to respond to comments over there but it's not easy - perhaps SkS readers can help me out :-)

Of all the people that doubt the science of climate change, geologists seem to be the most vocal. But they, of all people, should be the most concerned.

I was headed to the Sydney ABC studio to talk about my new book on climate change denial. What was unique about this interview was my coauthor Haydn Washington and I would have the opportunity to answer questions from callers. Considering the topic at hand, we expected some demanding questions from those who doubt the climate science. On the way, I declared to Haydn I'd put money on someone bringing up past climate change. In every interview over the weeks following the launch of our book Climate Change Denial, the same question always arose: "Climate has changed naturally in the past so how do we know current climate change is caused by humans?"

Haydn wisely didn't accept the wager. And sure enough, the first caller (listen) introduced himself as a geologist and proceeded to discuss past climate change. Afterwards, I reflected on geologists and the perception that they tend to be sceptical about human-caused global warming. Australia's most well known skeptic, Ian Plimer, is a geologist, as is another well known sceptic Bob Carter. But is the characterisation that geologists are mostly sceptics accurate?

One survey of earth scientists found that while 97 per cent of actively publishing climate scientists agree humans are changing global temperatures, only 47 per cent of economic geologists (those who study geology with a view to its commerical exploitation) concur (pdf). In fact, among all earth scientists, economic geologists are the most sceptical.

Similarly, in response to the consensus on global warming, the American Association of Petroleum Geologists "respects these scientific opinions but wants to add that the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data". You'd call that type of endorsement damning with faint praise.

However, the broader community of geologists seems convinced by the evidence that humans are causing global warming. The European Federation of Geologists says climate change is predominantly caused by anthropogenic emissions of CO2 and poses significant risks to human civilisation. The Geological Society of America concurs that "greenhouse gases have been an increasingly important contributor [to global warming] since the mid-1800s and the major factor since the mid-1900s". The Geological Society of London states that "evidence from the geological record is consistent with the physics that shows that adding large amounts of carbon dioxide to the atmosphere warms the world and may lead to: higher sea levels and flooding of low-lying coasts; greatly changed patterns of rainfall; increased acidity of the oceans; and decreased oxygen levels in seawater".

So climate scepticism seems strongest among geologists closely linked to the mining and fossil fuel industries. Perhaps the words of Upton Sinclair shine some understanding on the forces at play here: "It is difficult to get a man to understand something, when his salary depends upon his not understanding it."

Regardless of motive, the question of past climate change is certainly an important one that provides much insight into how our climate behaves. Plimer's conceit is that as a geologist, he has taken into account Earth's past while climate scientists have ignored it. This is a curious position considering there is an entire field of climate science, paleoclimatology, that examines past climate change. What do they find?

Climate has changed in the past. Sometimes it changes quite dramatically. Why? When something causes a change in global temperature, such as varying solar activity or changes in the Earth's orbit, feedbacks amplify these changes. The atmosphere grows more humid and as water vapour is a greenhouse gas, this traps more heat. Arctic sea ice melts, causing the exposed ocean to absorb more heat. The feedbacks aren't so large that they lead to runaway warming but they are enough to amplify one degree of greenhouse warming to three degrees of total warming. Many different periods throughout Earth's history, from the last few millennia to millions of years ago, yield remarkably consistent results establishing this amount of climate feedback.

When geologists bring up past climate change, they're actually citing evidence for climate feedback. Dramatic swings in global temperature, dragging the planet in and out of ice ages, are possible because of these feedbacks. Renowned paleoclimatologist Wally Broecker sums it up beautifully: "The paleoclimate record shouts out to us that, far from being self-stabilising, the Earth's climate system is an ornery beast which overreacts to even small nudges."

We have already given our climate a big nudge. How do we know it's us causing the warming and not natural causes? Because we've directly measured it. Satellites measure reductions in heat escaping to space - direct empirical evidence that carbon emissions are trapping heat. Surface measurements measure more heat returning to Earth, confirming the increased greenhouse effect. We see many signatures of greenhouse warming such as winters warming faster than summers, cooling upper atmosphere with warming lower atmosphere and nights warming faster than days. The case for human-caused warming is based on many independent lines of evidence.

The feedbacks that amplified past climate change are now amplifying the warming caused by our carbon emissions. We're measuring more water vapour in the atmosphere, a strong feedback. Arctic sea ice is disappearing and satellites measure less sunlight reflected back to space - another significant feedback. The Earth's past and modern measurements all paint a consistent picture - our climate is already overreacting to our "nudge".

The peer-reviewed literature on past climate change sends a strong message, in stark contrast to what we hear from petroleum geologists. Past climate change is not a source of comfort. It's a cause for concern.

Comments

To CG's list (which I would agree with except last one), I add:low mathematical skill level. Strong math isnt a perquisite for geology which leaves many geologist poorly equipped to follow papers where the skill is assumed.

Sorry... But I know very well where many of my colleagues get the arguments they cite. They could NOT come up with these things on their own. Many just passively receive emails from other colleagues citing certain "factoids" and arguments that appear on the internet, and then proliferate through the right-wing blogosphere with almost unimaginable speed. (I've researched this phenomenon on many occasions. Do a Google search on a unique key phrase (in quotes) from the latest Denialist argument, and see where it shows up.)

Many or most of these sites are overtly political in nature. You be the judge of the political orientation. I'm not saying that left-wing, or environmental activist sites are immune from exaggeration or misinformation. Far from it... but climate change evolved from a scientific issue into a political issue when it was embraced by right-wing groups. You can disagree if you wish, but the empirical evidence supports this observation.

The mathematical skills of geologists span all possible levels of proficiency from minimal to extremely sophisticated. While it's possible to be a good geologist while having minimal math skills, your argument holds little merit in my opinion.

[DB] Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

CG - we both have to work from personal experience. I had not noticed any right wing bias in my colleagues. However, if they are into denial (none that I know of in my institute), then yes, I would expect that they get their info from right wing climate denial sites.

And to GC as well, I am not saying that all geologist are mathematically challenged (my degree is in geology with maths minor). I am saying that you can hardly do climate physics (or physics period) without maths. In my experience, few geologists by way of contrast take maths beyond first year at uni. This does put them at a disadvantage in reading papers on climate physics or the intricacies of PCA. GC - your faith in McIntyre is touching. I would have more respect if he was publishing rather than taking cheap shots from the sideline.

I'm a geologist/palaeontologist myself, and know many geologists here in Australia, and overseas. The majority of them accept that AGW theory correctly describes what's going on (a few are skeptical that we can do much about it anymore); Mike Sandiford, my lecturer in metamorphic geology, now at Melbourne Uni, is a strong advocate of AGW (Ian Plimer used to work at Melbourne Uni, but there is little respect for his academic prowess here, partly due to his very meagre publication recordl; and yet he is touted as Australia's most renowned geologist). I have actually collaborated closely with Bob Carter in the late 90s, and have respect for his work in marine geology, so it is disappointing that he is undermining another field of science, blatantly due to political convictions (Heartland Institute, srsly?).

Geology is vitally important in understanding what's going on (I'm involved in organising a conference on the relevance of palaeoclimate on today's climate change in the next year), and geologists should be very involved in the whole thing. But scientists must understand that expertise in one subject does not automatically translate to others. And interestingly, the geologists more closely involved with climate (palaeontologists, palaeoclimatologists, etc) are much more likely to agree with AGW theory than those who are far removed: economic geologists can get a degree (or just go straight to a job) without ever doing any classes outside of ore formation or hard rock geology, which are as relevant to climate as inorganic chemistry is to evolution. Indeed, we see similar patterns in lists that supposedly show scientists denying evolution.

Ginckgo - that is very encouraging to hear. I'm sure there is a division between the hard rock people and the others; and there is of course no reason why geologists shouldn't contain the whole political spectrum among their ranks just as other disciplines do (there are certainly, for example, right wing biologists, whose political attitudes greatly influence their approach to conservation matters, a not unrelated topic).

It is just a pity that the media, and politicians, take the views of "scientists" to climate change as if these are generic, no matter what the actual discipline involved nor the political mindset and affiliations, as if Carter (for example) speaks with a pure clear voice on climate change. Mind you it suits them to do it, which is why Alan Jones, for example, chooses geologists, not climate scientists, to talk about the subject.

I think it has also taken a long time for those of us who are scientists to realise that political matters do impinge strongly on the way some of us present science. Perhaps we were naive to think that science would be uniquely free from this. if so, the climate change "debate" and its significance for the planet, has shaken that naivety away.

David Horton: Over at WUWT the other day someone pointed out that science is apolitical, but scientists aren't (which is correct as far as it goes). They can't seem to see the irony of saying this on a site that is all about attacking the scientists and not the science.

I'm still working up the courage to ask my best friend, who works for a state geological survey, if he doubts AGW - he studies palaeo with me, but is now in charge of state support of mining exploration. I guess it would confirm that a link with primary industries taints your view of the science that could impact your sector.

You won't see me again on this site. If you miss me, why not drop in on "Brave New Climate", "tAV", "Digging in the Clay" or "Musings of the Chiefio".

My Parthian shot. As Ronald Reagan said to Jimmy Carter, "There you go again". You made a personal attack on Steve McIntyre rather than address his point about the inversion of the Tiljander data:
( - Off-topic link snipped - )

I will read your rebuttal with interest although I will not reply, thus giving you the satisfaction of having the last word.

For more than 30 years I have been working to improve the environment, starting with cleaning up the river Thames in the late 1970s. We are on the same side even though we may differ on issues relating to CO2. Here are some links that cover my personal views. I would appreciate your comments if you have the time:
http://morcombe.net/Senate/Spruyt1.doc
http://bravenewclimate.com/2011/05/15/solar-power-in-florida/

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Response:

[DB] First of all, your original comment was deleted due to being off-topic (and NOT by me).

Secondly, complaining about moderation when the very act of posting a comment on this site is an acceptance of any needed moderation is a certain invitation for yet more moderation.

Thirdly, this site's moderation offers up a venue for some of the best science-based dialogue available on the internet (bar none), as many participants here will attest.

While well outside my expertise, I'd happily comment on CA stuff - if he published it. That is the way scientific conversations are held. Whether he has a good point or not about Tiljander or not, I dont know, but it wont affect the science unless he publishes. His past behaviour on CA does not endear him to me, and his lack of publishing suggests his motives are political not scientific.

As long as we are all coming out :) I hold qualifications in geology and geophysics.

To be honest I haven't worked in the field for a good ten years having moved back to a real life with kids and family in a big city.

Anyway to cut a long story short as a former geologist I have been surprised at the number of my fellow "geologists" on the denial side of the argument.

I admit when I first heard of GW I thought I had heard it all before but when I took time to read the work going on into GW I quickly came around to the consensus view.

This is where I find it hard to understand why "geologists" would doubt the science. For me anyway knowing the earth's history better than most helped me better understand the difference between past events and what is occurring today.

As a "hard rock" geologist with interests in mineral deposits (and mineral carbon sequestration), I find this meme extremely tedious. Yes, some geologists are in denial about AGW, so are some physicists, electrical engineers, doctors, etc. Get over it.

Also, the notion that geologists are lacking in the basic sciences and math depends on where they have gone to university. In the US, most geology majors are required to take a year each of calculus, chemistry and physics. That is unfortunately not true here in New Zealand.

About the "left-wing conspiracy" bit: I've come across many different versions of that argument.

- an imperialist conspiracy to keep poor countries poor
- a Thatcher conspiracy to harm labor rights (don't ask me to explain...)
- an Al Gore conspiracy to raise taxes (I wonder how the Gore family managed to co-opt Tyndall back then. Very long term goals!)
- a developing country plot to harm American and European economies

DSL
Garethman, I have to take exception at your use of "alarmist." You imply that "alarmist" and "denialist" are binary opposites. That's clearly not true. You also fail to define "alarmist." Can you point out any poster on this site who you would consider to be an "alarmist"? And could you point out any climate scientist who you consider to be an "alarmist”?

Garethman.
Hi DSL, I have this idea that human beings cover a range of beliefs and emotions. Therefore, logically there are alarmists if if we recognise there are any other type of personality. If you are happy to see denialists in the post, you must ( or hopefully!) also have the understanding that terms are relevant and subjective and if you are OK with using them, I imagine you are happy to extend that right to others..
My main point, to return to the discussion point was that the previous poster had correlated “denilaism” with Geologists of a certain age. It has been my observation of young people in Climate camp etc, that they are much more radical in their beliefs, in fact to the extent that they occasionally do not believe evidence should ever be used to prove or cast doubt on Climate change, we should just believe. Any contrary evidence should be suppressed, cars should be banned and veganism imposed by law. You get the picture
This is healthy. Don’t panic or be alarmed. Young people go through this phase, it’s part of their development. Old duffers like myself tend to take more persuasion to move from our life long beliefs. Hopefully we all get there eventually and we all believe we must do something constructive to stop the damage being inflicted on our environment by ourselves. As long as we are not too “holier than thou” It’s a pretty broad church.
By the way, I don’t think alarmists are on the opposite pole from revisionists , But I do think they are on the same continuum from complete and utter obsessive adherents tolerating no questions or doubts, to complete doubters who do not think in a logical or evidence based manner and are not really connected to the world as we know it.
You are also right, in I have not seen any of them on this wise site, but if they are human, trust me, they are out there. Maybe someone could propose a continuum correlating professions to their place on the line? Such pigeon holing or reductionist concepts would provide at least entertainment if lacking methodology or illumination.

garethman wrote : "It has been my observation of young people in Climate camp etc, that they are much more radical in their beliefs, in fact to the extent that they occasionally do not believe evidence should ever be used to prove or cast doubt on Climate change, we should just believe. Any contrary evidence should be suppressed, cars should be banned and veganism imposed by law. You get the picture"

Picture ? More like a fantasy story created to try to claim that there is a hidden and evil left-wing Stalinist/Leninist/whateverotherLeftist conspiracy comprising tyrannical lefties (did I mention the Lefties ?) who want to drag us all back to caves, where we can eat grass and dirt on pain of death.
Get a grip.

Touble is, garethman, we're a wee bit short on evidence that casts any significant doubt on the prevailing theory of climate. In fact most evidence emerging tends to paint a picture of effects happening more rapidly than previously thought (e.g. Arctic ice melt). I'm rapidly getting to a certain age, and I enjoy a good steak, but I see the scientific rationale behind cutting carbon emissions a.s.a.p. very clearly indeed. There is no (sensible) two sides to the science - if there are sides, it's either that climate disruption, already arriving at a doorstep near you, is bad or it's very bad, take your pick...

Chill out folks! I’m not casting doubt on climate change, though for some reason this is continually read into my posts. I am interested in the human reactions to the science, the depth and breadth of emotion. It’s a painful subject for some, but fascinating all the same.
Incidentally anyone who does not believe young people have more radical ideas than older people and say things they later takes a differing view on are probably in denial with regard to human behaviour and should probably go and visit a University campus to see such dynamics in action. http://www.climatecamp.org.uk/
The same with climate camp. I have camped in the same field with these guys for weeks at a time. They are enthusiastic and radical, but objective? maybe not, but it’s reassuring to see young people still have heart and are motivated to try and change the world for the better. They will be at Glastonbury again this year, if you are lucky enough to get a ticket, go and visit them, I’m sure they would rustle up a cup of tea and inspire you.
What I do wonder judging by reactions to my posts is whether a lot of the odd anger expressed at posters who give contrary views or those who question evidence is misdirected. A common feature of human behaviour is that people will express anger at a subject unrelated to the cause of their anger, because it is unacceptable to express anger at the real thing. I see Right wing individuals railing at everything from immigration to climate change, when on an individual basis they are probably upset at their lack of success in life, or their family dynamics. Whenever you see an "over the top” reaction to an innocuous situation or post you can be fairly sure that it is anger expressed in an inappropriate direction.
I think it’s also a mistake to call belief in science “blind faith” I have not seen any sign on this site that supports such an idea, or indeed that evidence is suppressed, and lets face it, the evidence for a warming climate is pretty conclusive. So it’s not blind faith, it’s not a religion, but our beliefs in the science and what we do about is are very much coloured by who we are. Perhaps the profession of forensic mental health are another group who are just an awkward bunch when it comes to climate change?

scaddenp @ 51,
I'm nor sure where you got your undergraduate degree, but the institute where I went, in the USA, there where a number of geology students in Advanced Calc., as well a sprinkling in Partial Dif. EQ. Our engineering group was also required to take a Geology course in Rheology, to expose us to "plastic" flow of materials So I would dispute you statement of a "low mathematical skill level". Now most engineer & science students may probably will not use all the tools they were taught, but at least they were exposed to a wide variety of tools, to think critically, and a significant number of lab hours, to show where theory and reality can collide.

One other point is the use of the "denier", conservative, etc. terms to denote those who have a opposite opinion. If one is sure of their position, one does not have to use that tone. What comes across is a "methinks thou protests too much" impression, and hence has to cover a weak position.

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Response:

[DB] Let's not make this personal. I'm sure the vast majority of participants here all have significant college/university degrees. Most of us have multiple degrees as well. Whoopee.

What matters is the quality and relevance of your comments and arguments.

J Bob @68, we call the deniers "deniers". They in turn, and before hand, accuse us of being "alarmist", "fraudulent", "conspiratorial", "dictatorial", "censorous", "traitorous", and "genocidal". From this you conclude that we protest to much to hide a week position?

Frankly, "denier" is not even an insult. An AGW denier is simply a person who denies AGW. In this case, that deniers take umbrage at what is a simple descriptive term shows they have a raw nerve about the quality of their arguments.

One other point is the use of the "denier", conservative, etc. terms to denote those who have a opposite opinion. If one is sure of their position, one does not have to use that tone. What comes across is a "methinks thou protests too much" impression, and hence has to cover a weak position.

Obviously J. Bob wasn't required to take a logic class in order to get his engineering degree.

The way denialist is used here it is a term that a reasonable person should take offence at. As it is used here it is an accusation of a lack of intellectual integrity. It is used to describe someone who is looking for ways to continue their belief that we do not have to take action to mitigate climate change rather than honestly looking at the science to see whether there is a danger. This is contrasted with a sceptic, who has doubts that were arrived at by honest enquiry.

Lloyd Flack @71 "denialist" may well be a term any reasonable person may take offence to, but that is not the term I used. It is also true that actual AGW deniers are also almost universally denialists as you have defined the term. That may give a certain insulting connotation to the term "denier" to those few deniers who do pursue the issue rationally, but the insult is in the association with their fellow travellers, not in the denotation of the word. If they liked the company they keep, there would be no insult. And certainly there are 'warmistas' (oh, don't you just love the subtle wit of your garden variety denier) for whom the connotation is very strong, but that does not change the denotation and that means deniers need not take insult except that they want to.

I should note that the deniers invited the re-appellation by calling themselves "skeptics" who are not, as you claim, people with doubts that where arrived at by honest enquiry. In popular usage, a "skeptic" is one who doubts, without any claim about their reason for doubting. In the other common usage, a "skeptic" is one who employs doubt as a method of honest inquiry. The deniers rely on the fist definition for the legitimacy of the term but then play on the second meaning to suggest that they, and they alone apply legitimate skepticism to AGW. So, for a catch all name, I have a choice of using the term "denier" which associates, but does not accuse, deniers of using tactics they almost universally use; or I can use the term "skeptic", thereby suggesting climate scientists do not use the skeptical methodology they in fact use.

Your definition does exactly that by conflating the two legitimate definitions. Employing it the deniers show exceptional hubris by defining themselves as having arrived at their opinion by honest enquiry, and beg the question as to how honest the inquiry was.

This discussion seems to be drifting a bit off topic, but I'll attempt to tie various issues together by observing that it has been my impression that many of my colleagues initially approached the issue of climate change from a skeptical perspective, but unwittingly slid down the slippery slope of "Denialism".

In this regard, it's important to recognize the role Denialist web sites, and books such as Ian Plimer's "Heaven and Earth", have played in perpetuating misunderstanding of the scientific arguments. (One of my colleagues actually purchased numerous copies of Plimer's book to mail to his friends in an effort to convince us that AGW is a fraud. Unfortunately for him, the book taught me more about Denialism than it did about climate science.)

Any sincere skeptic can potentially find out what science has to say on specific issues through web sites such as SkS. If they then remain doubtful of the validity of the prevailing view, this is what science is all about (assuming it is for legitimate reasons).

At the same time, it's important to recognize the corrupting role that "cherry picking" and "affirmation of beliefs" plays in this process, and why bias is so difficult to avoid. If in an overly zealous effort to question the prevailing theory, one immerses one's self in "Denial World", and if this is all one sees day after day, it becomes easy to believe there's no valid scientific basis for AGW.

There are reasonably well defined criteria to distinguish skepticism from Denialism, and continued arguments that "Denialist" is nothing but a meaningless insult become very tedious. Any sincere skeptic should acknowledge that AGW Denialism is real, and should distance themselves from it as much as possible.

Unfortunately, this is a step few ardent Denialists are willing to take, as they quickly discover that outside of "Denialworld", the arguments against AGW are as thin as Arctic sea ice.

I also would like to emphasize the important contributions geologists have made to science in general, and to climate science in particular.

J Bob. The point is proportion of them doing maths. I did maths papers to masters level, but the majority of my cohort only did maths in their first year. The point is that it is perfectly possible to do geology with only 1 year of maths. Its not possible to climate science with that. A fairer way to evaluate my comment would look at average maths skill in geologist versus physicists.

There is evidence of a dimming event, capable of affecting global hydrology from INDOEX; a very comprehensive field study conducted in equatorial Indian Ocean during 1999.

Briefly, the 250 scientists of INDOEX discovered a massive atmospheric cloud of mostly man-made pollution from fossil burning, covering an area the size of Australia extending upwards 3 to 4 kms, was reducing the sun’s ability to create evaporation.

Subsequent monitoring by Prof. V. Ramanathan of USC, determined this cloud remains stationary for 3 to 4 months yearly due to an inversion, with one of its adverse effects being regional drought.

Those supporting the global warming case have long argued these clouds of pollution have aided in arresting temperature increases. INDOEX distinguishes the effect over this body of water has catastrophic consequences.

The question is – why have Australian climate scientists pushing the CO2 warming barrow failed to acknowledge such a momentous climatic happening?

Could the answer be - an identified physical cause of change totally destroys the greenhouse gas hypothesis?

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Moderator Response: [Dikran Marsupial] Fixed URL (hopefully that is the one you intended). Can you supply a verifiable reference to the findings of Prof. Ramanathan?

By the way, Denier, I'd like to see the logic and evidence that differentiates your proposed hypothesis of "an identified physical cause of change totally destroys the greenhouse gas hypothesis" from "this means a significant change in the number of peanut butter and jelly sandwiches in Argentina." In other words, why do you propose your final hypothesis? What does this alleged cloud of pollution have to do with the physics of radiative transfer? And AGW is not an hypothesis. It's a theory based on a broad range of already well-tested hypotheses.

Dr. V. Ramanathan is the Distinguished Professor of Atmospheric and Climate Sciences at the Scripps Institution of Oceanography, University of California at San Diego. In the mid 1970s he discovered the greenhouse effect of CFCs and numerous other man-made trace gases. He correctly forecasted in 1980, along with R. Madden, that the global warming due to carbon dioxide would be detectable by the year 2000. He and his students also used satellite radiometers to detect the atmospheric greenhouse effect directly from observations and demonstrated using satellite and ground based observations that the coupling between atmospheric warming and water vapor greenhouse effect exerted a strong positive feedback effect, thus confirming earlier model predictions. Teaming up with NASA colleagues, he showed that clouds had a large natural cooling effect on the planet using direct measurements of the atmospheric greenhouse effect. He, along with Dr. Paul Crutzen, led the Indian Ocean Experiment (INDOEX) that first discovered the widespread South Asian Atmospheric Brown Clouds (ABCs). Using INDOEX, Dr. Ramanathan showed that the South Asian brown clouds led to large scale dimming of the ocean slowed down the monsoon circulation and decreased monsoon rainfall. He followed this with a path-breaking study with agricultural economists to show that ABCs and greenhouse gases were responsible for a 14% decrease in rice harvest in India. In 2006, he used miniaturized instruments on light weight unmanned aerial vehicles, UAVs, to show that black carbon in ABCs are causing a large heating of the atmosphere over Asia, linking ABCs to the melting of Himalayan and Tibetan glaciers. During the summer of 2008, he used these UAVs to track pollution from Beijing during the Olympics. His most recent publication suggests that human activities have likely committed the planet to exceed the threshold for several climate tipping points during the twenty first century. Dr. Ramanathan currently chairs the UNEP-sponsored ABC Project with science team members from the USA, Europe, India, China, Japan, Korea and other Asian countries. He is the recipient of many national and international awards such as: the American Meteorological Society's Rossby medal, the Buys Ballot medal by the Dutch Academy of Sciences, the Volvo environment prize in 1997 and the Zayed International prize for environment in 2008. He has been elected to the American Philosophical Society, the US National Academy of Sciences, the Pontifical Academy of Sciences by Pope John Paul II, the Academia Europea, the Third World Academy of Sciences and most recently to the Royal Swedish Academy of Sciences. He chairs the National Academy of Sciences panel that provides strategic advice to the US Climate Change Science Program (CCSP), a $2 billion/year inter-agency research program. He is part of the Nobel Peace prize (2007) winning Intergovernmental Panel on Climate Change since its inception, and for the 2007 report served as one of the lead editors in IPCC-AR4 (2007), WG-I. A more complete resume and bibliography can be seen at: http://www-ramanathan.ucsd.edu/."

OK, he discovered the global warming effect of several trace gasses, predicted the GH warming of the atmosphere in the 1980's, has been a participant in the IPCC since 1990, and a lead author in AR4. But he is obviously not an "AGW scientist" because he is leading the effort to find out about the Indian Ocean Brown Clouds, which you tell us the AGW scientists are ignoring.

"Far more profound are the chemical and biological effects of global human activity. It may seem remarkable that changes to mere trace components of the Earth’s atmosphere—CO2, methane (CH4), and so on—can so fundamentally impact the Earth. Nevertheless, the concept of control of surface temperature by levels of greenhouse gases (GHGs), as originally worked out by Arrhenius (10) and Chamberlain (11), has been vindicated by subsequent work. Today, the rise in CO2 to over a third above preindustrial levels has been demonstrated beyond reasonable doubt: by systematic measurement since the 1950s (12); and by the record of atmospheric composition, now nearly a million years long, preserved in Antarctic ice (13).

The rise in temperatures, that, at high latitudes, already exceed modeled predictions, has important consequences. The fringes of the great polar ice-sheets, once thought to react sluggishly to temperature rises, are now seen to respond quickly and dynamically (14). The ensuing sea level rise, scarcely begun, may ultimately be of the order of several meters (15) if temperatures rise by some 2−5 °C, as predicted (16).

Global temperature rises will have far-reaching consequences for the biosphere. Species will migrate (if they are able to) to track their optimum climate belt, a phenomenon more pronounced in the oceans than on land (17): changes in, say, larval hatching times can cause cascade-like changes in entire ecosystems, when these larvae act as food for other animals."

But again, he can't be one of those "AGW scientists" because he, like Ramathan is a Co-chief scientist of the INDOEX program, and as you inform us, this is an issue being ignored by AGW scientists.

Dirkran Marsupial @ 78,
it's been a couple years since I last looked at the ABC, and have not looked at it from a drought perspective. My interest then, was looking at the thermal radiation & convective effects of the particulates.

However, some time ago I noted the use of solar ovens instead of wood fires, for cooking, and their effect on saving trees, and reduced erosion. This report (Machine Design, if I recall) was about the high elevations of Northern India, Nepal, etc. It's simplicity and resultant effects was an engineer's delight.

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Moderator Response: [Dikran Marsupial] No problem, I was just wondering if there was a genuine contradiction there, it seems perhaps not.

Sorry about the wild leap in good fun. Moved over here to be more on topic.

The point is that once we reach the limit of certainty bestowed by the wonderful equasions we are blessed to have in fluid dynamics and are forced to describe apparently chaotic features with perameters, we become far more like the poor geologist out in the hot sun of uncertainty, picking at rocks that seem to indicate a wildly chaotic history for our planet.

To the reasons geologists tend to be skeptical already well descried in this thread I would like to add Milankovitch.

Before Shackleton and the fan club of foraminifera Milakovitch had been carefully studied by gologists for many years and found wanting because his orbital variations had little explanatory power in earth history.

How do you get a proterozoic glaciation, an ordivician glaciaton, a permian glaciation, and our current glaciation, all separated by roughly 200 million year interludes of much higher temperatures and CO2 levels from Milankovitch?

If Milakovitch explains why CO2 is the slave to temperature in the ice cores, where was he during the mesozoic?

Your comparison is not even as close as apples and oranges; more like bananas and elephants. Take all data and facts into consideration, especially continental drift. What was the continental configuration during those times? How did that affect ocean currents? How about shallow seas and mountain systems that existed then that do not exist now.

trunkmonkey I don't think the proterozoic/ordovician/permian glaciations have been attributed to Milankovic cycles. Milankovich cycles are not the only thing that peturbs the carbon cycle. For example, the position of land masses affects the weathering thermostat. If the landmasses are concentrated at the equator, weathering increases because the equator is warmer than the extra-tropics and CO2 tends to fall.

If you are genuinely interested, see the excellent book by David Archer, reviewed here.

The Milankovitch Cycles drive the alternation of glacial and interglacial periods within an ice age. Whether we have an ice age or not is determined by other things. The most important of these is continental configuration.

If you were a good geologist you would understand about timescales. Milankovitch operates effectively at timescales of less than about a million years or so, and require a global configuration of continents that is sensitive in such a way that the small Milankovitch variation can trigger ice ages. On longer timescales, the movements of continents (e.g. closure of Panama, uplift of Himalaya, isolation of Antarctica), drive the likelihood of the globe being sensitive to a flickering switch of glaciation. The cooler Sun in distant geological past also allowed for deeper glaciations than at present, but the individual flickers of glacial periods analogous to the Devensian, Anglian or other phases are generally not clearly resolved in the existing geological record, and of course we can't define the orbital variations hundreds of millions of years ago that might have been in operation to pace the glaciations.

Milankovitch, of course, was just a mere twinkle in the eye of a small furry creature in the Mesozoic... The small furry creature was enjoying a geological and CO2 configuration that favoured high global temperatures and little ice cover.

I have to agree with Mike Palin (#61) that this is a quite tiring meme which I thought would be beneath SkS. Yes, there are some geologists that deny AGW but as was pointed out in the original article most of us don't. Also, lumping together hard rock geologists who work and study things that have very little to do with climate with Quaternary geologists and palaeoclimatologists who provide vital data for our understanding of AGW (most of our knowledge about the normal variability of the climate, data to validate the computer models and the possibility to use previous climatic events for comparison with the present depend on the work of geologists) is highly problematic.

Many geologists do have a good understanding of math and those who don't mostly work in field where it is less important. It is true that advanced math skills are needed for many types of climate science, but palaeoreconstructions often only requires fairly simple statistical approaches. On the other hand many modellers can't identify a climatic or environmental change in a sediment succession or distinguish between an arctic or boreal fauna in a sample. That's the whole reason why we need collaborations and multi-disciplinary research. I believe that these kinds of discussions are detrimental for such work.

#33, MajorKoko, besides the link from DSL showing that a positive feedback is not necessarily a runaway feedback it is worth noting that there is at least one major negative feedback effect which is important for earths climate, the weathering of bedrock. On very long timescales (millions of years) a warmer climate will lead to more weathering and thereby a decrease in CO2 in the atmosphere (since CO2 is used in the process). Unfortunately this effect is extremely slow so it won't have any significant effect on the timescales we are worried about (hundreds to thousands of years).

The continents are more widely dispersed today than they have ever been in the last 600 million years. There have been a couple phases if amalgamation and disintegration, but over the vast perponderence of this time there has been some sort of panthalassic ocean and a cluster of continets. The Pacific is in some sense a relict panthalassic.

There has almost always been a continent at the south pole. There has never been one at the north pole.

Glacial periods have occurred in many different configurations.

To a geologist focussing on the pleistocene or even the tertiary is cherry picking. Why is the range of internal variability constrained by anything less that the range of variablity since the proterozoic?

trunkmonkey The answer to that question ought to be obvious. To get the degree of variability seens since the proterozoic you need major changes in the configuration of the continents. The configuration of the continents has changed very little during the pleistocene, so one ought to expect much less variability than witnessed since the proterozoic. AGW has occurred only during the pleistocene, so it is the variability of the pleistocene that is relevant to the discussion of AGW.

Thank you Moderator [Dikran Marsupial] that is the INDOEX link in question.

In respect of your request for more info. concerning Prof. V. Ramanathan, the following is a must watch -2009Lecture_Ramanathan.wmv

The location and magnitude of the ABC and the resulting loss of evaporation would most likely affect Australia.

The importance of the weather role of the Indian Ocean and linking it with the extensive drought of southern Australia was revealed by UNSW early 2009.

It should be noted the eastern part of Australia was rescued from drought by a freakishly intensive La Nina, whereas WA is still suffering drought.

00

Moderator Response: [Dikran Marsupial] no problem, link to video activated. I've only watched the first five minutes so far, but Ramanathan seems to be rather concerned about greenhouse gasses, and in particular carbon dioxide. At 17:42 Ramanathan shows a plot of major shifts in rainfall over the last 50 years. Australia is not highlighted, that rather suggests to me that Ramanathan provides no support for your speculation. But I'll keep an open mind for the rest of the talk. O.K., having watched the rest of the video, AFAICS it provides no support whatsoever for your assertion. Firstly it suggests the major change in rainfall is concentrated on equitorial Asia, India and Africa (with relatively little change in Australia). Secondly Ramanathan clearly identifies CO2 as the major problem. Thirdly Ramanathan is clear that dealing with ABCs is only a temporary fix that will buy some time to deal with CO2, but nothing more. Fourthly Ramanathan's findings are mainstream science, he identifies where it is discussed in the IPCC WG1 report (I should think we have all seen that diagram)
I do recommend people should watch the video.

truckmonkey - try looking up "faint young sun". As to others, they were answered in models thread but it appears you seem determined not believe the evidence there. That weather is chaotic is obvious. Likewise the fact we have seasons for starters should tell you that energy balance has chaos on a string as does the evidence that climate responds the applied forcing rather than in some random way. If you are determined to ignore evidence, then there is little further to be said.

Sorry I missed this post the other day, John. As a geologist with a background in minerals, I'm familiar with the subject.

Yes there are denialists who are also geologists, but apart from the fact they are geologists they typically fit into the classic denier frame in demographic terms. The latter is more relevant.

I've met geologists who use their knowledge of the past to state the bleeding obvious: "The climate has always changed". My standard response is that "Indeed it has, but the last time, there was not a civilisation in the way"!

I've met geologists who use their knowledge of the past to state the bleeding obvious: "The climate has always changed". My standard response is that "Indeed it has, but the last time, there was not a civilisation in the way"!

Denier geologists who use this argument are particularly math-challenged. It's not just climate change that's the issue; it's the *rate* of change that poses the biggest challenges. Using denier geologist logic, I could argue that driving your car into a tree at 60 mph is no problem. After all, cars have decelerated from 60 to 0 with no harm to the passengers countless times in the past. Therefore, only auto safety alarmists would argue that folks shouldn't drive their cars into trees at 60 mph.

I don't see what the faint young sun has to do with Milankovitch and ancient glacial periods.I hope you are not shoehorning me into the "CO2 was high during the Ordovician glaciation" foolishness. One of my first comments on this site was that the relationship between temperature and CO2 so striking in the ice cores should be extended to all of earth history.

Even though there is no direct evidence for a faint young sun and all we have is inference from the apparent evolution of similar main sequence stars and the foundation of Hertzprung-Russel was shaken by the surprising supernova from a blue giant in the 80's, I'm inclined to believe if you find a better word than "faint" and give me some really big error bars on the magnitude.

Seasons are Milankovitch on steroids.

You are well aware of my problems with the mid pleistocene transition.

Geologists studied the positions of the continents in relation to prior glacial periods long before computer scientists developed an interest. I was going to post images of the continental positions during the three prior glacial periods but I saw DB admonishing norman against such eyecrometer analysis. I am old school enough to trust the two photon detectors on the front of my head, so check out the beautiful work of Ron Blakey at nau.edu.

trunkmonkey, the faint young sun is also directly predicted by the physical theory of stellar evolution. Consequently any evidence for that theory is evidence for a faint young sun. As I understand it the physical theory of the faint young sun is very well confirmed.

Further, the direct evidence is not just the apparent evolution within the Hertzprung-Russel diagram, but also the correlation between helium concentrations and luminosity for stars of similar mass. Admitedly mass is normally determined by position on the Hertzprung-Russel diagram (although it can be determined independently for binaries), so that may be what you are referring to.

Further, the luminosity of various stars which are just forming, and hence not yet in the main sequence also provide evidence for the faint young sun.

Truckmonkey, are you looking for a coherent model for a reality or looking for excuses to ignore climate science?

As I interpret your remarks, you are claiming that past climates cannot be explained by known climate physics. Well, the best model we have (practically uncontested unless you count the "iron sun" crowd) gives us faint young sun and with it an explanation for cold episodes despite high GHGs. The fact that you get season and response to Milankovich is evidence that climate is not a random chaotic process but controlled strongly by the forcings present at the time.

Continent position modulates albedo effect as land at high altitude assists in maintaining summer ice - but it is ONE parameter in the whole equation.

There are two important notes on deep paleoclimate.
1/ Uncertainty with forcings. If you were asked to set up model for some early period, then finding values for fundamental variables, like land albedo, continental position, solar constant, atmospheric composition and rate of volcanism, is fairly challenging and so gives you a range of climates. What you are looking for and wont find is a configuration that cant be explained in terms of the likely range of forcings.

2/ Multiple hypotheses does not challenge climate physics. Having more than one way to create a past event (eg the mid Pleistocene transition) is not the same as having no hypothesis. It means that at present there is insufficient data to constrain the possibilities. It would only be relevant if any the hypotheses had an implication for present day physics.

Garethman, you may not see this as it seems I'm always too late to "denier" discussions, but I think you have hit on something with this:
"So it’s not blind faith, it’s not a religion, but our beliefs in the science and what we do about is are very much coloured by who we are."

To me this gets to the heart of the issue of those who deny the science of climate change. To trigger psychological denial, a fact must threaten a core belief or value, in other words, it threatens "who we are". My question is, what are the threatened beliefs that trigger climate change denial? I have some ideas I have expressed, but what do you think?

Dr. Bryan Lovell, President of the Geological Society of London and former senior executive of British Petroleum, in his book, Challenged by Carbon, argues that geologists can find evidence in a form most convincing to them, i.e. in the rocks, that the dramatic anthropogenic alteration of the Earth's atmosphere now underway has an historical analogue in the PETM and he warns that civilization must not allow this situation to continue. He writes about how it was that the European oil companies came to support nations signing the Kyoto agreement as opposed to US companies who continued on funding the climate science denial campaign. See: http://theenergycollective.com/david-lewis/47403/oil-industry-insider-expos-what-it-took-wake-some-them-climate

Lovell's mantra is "you can't argue with a rock", a phrase which presumably has resonance with geologists. Refer recalcitrant geologists to this book the next time you are faced with one who denies climate science - the Geological Society of London is the largest such society in Europe and the oldest in the world.

On another point: I would like to add to the famous quote from Richard Feynman (The Pleasure of Finding Things Out page 142) i.e:

"I believe that a scientist looking at nonscientific problems is just as dumb as the next guy - and when he talks about a nonscientific matter, he will sound as naive as anyone untrained in the matter"

I would change this to: Scientists looking at problems outside their own field of expertise can be just as dumb as the next guy, as illustrated by some geologists. But we can point to some climate scientists to confirm this as well.

For instance, I think some of James Hansen's opinions, most notably when he said for publication at the peak of the most intense media spotlight climate change has ever experienced during the Copenhagen negotiations that he hoped the negotiations would fail, because his opinion was not about climate science but was about politics and the likely effect of cap and trade vrs a carbon tax, also illustrate my modification of Feynman's statement.

For that matter, your own (John Cook's) statements on nuclear power in your recent book Climate Change Denial illustrate this point. How else can we explain what is published in that book in your brief critique of nuclear power? (see: http://www.skepticalscience.com/Climate-Change-Denial-book.html comment 25.